1. Technical Field
The present invention relates to an electro-optical device, such as a liquid crystal device, and an electronic apparatus, such as a liquid crystal projector, including the electro-optical device.
2. Related Art
When incorporating the above type of electro-optical device into, for example, a liquid crystal projector, because of the positional relationship of the elements of an optical system, it is sometimes necessary to invert images, and more specifically, to vertically invert images or to vertically and horizontally invert images. For example, in a multi-panel color projector including three liquid crystal devices as light valves, for example, red (R), green (G), and blue (B) light valves, white light is emitted from a light source and is separated into different colors of light components after passing through a half mirror, a mirror, a prism, etc., and then, the individual color components are modulated by the corresponding light valves and are again synthesized into one light component. During this process, some light components are reflected by the half mirror an even number of times, while the other light components are reflected by the half mirror an odd number of times. Accordingly, among the R, G, and B light valves, it is necessary for, for example, the G valve, to invert images of the G color. If Liquid crystal projectors, regardless of whether they are a single-panel type or a multi-panel type, can display, for example, vertically inverted images, such liquid crystal projectors can be used as a floor-installed type in which liquid crystal projectors are installed on the floor and as a ceiling-fixed type in which liquid crystal projectors are fixed on the ceiling upside down.
To perform such display inversion, a display device that can switch the scanning directions of scanning line drive circuits is disclosed in, for example, JP-A-2004-139111, by the same assignee as that of this application. According to the technique disclosed in that publication, bidirectional shift registers that can perform two-way operations are used for scanning line drive circuits, and by switching the scanning directions of the bidirectional shift registers, display can be switched between standard images and inverted images.
In the above-described related art, however, a control signal for reversing the scanning direction (hereinafter referred to as the “reverse-direction control signal”) should be supplied from an external circuit, separately from a control signal for the standard scanning direction (hereinafter referred to as the “standard-direction control signal”). It is thus necessary to provide an external-circuit connecting terminal for the reverse-direction control signal and also to provide dedicated wiring extended from the external-circuit connecting terminal. Additionally, since a wiring path for supplying the reverse-direction control signal, for example, from the external-circuit connecting terminal to the scanning line drive circuits is long, the reverse-direction control signal may be influenced by noise from another circuit, causing differences in the phase, amplitude, waveform, etc., between the standard-direction control signal and the reverse-direction control signal.